What Is A Codec?

As the page on codecs at Wikipedia says: "A codec is a device or computer program capable of encoding or decoding a digital data stream or signal. The word codec is a portmanteau of "compressor-decompressor" or, more commonly, "coder-decoder". A codec (the program) should not be confused with a coding or compression format or standard – a format is a document (the standard), a way of storing data, while a codec is a program (an implementation) which can read or write such files. In practice, however, "codec" is sometimes used loosely to refer to formats."

Codec Installations

Available Codecs for Debian

Many codecs are already available in the official Debian archive. These include codecs for MP3, H264, and AAC encoding and decoding. These codecs are made available through libraries such as the libav/ffmpeg libraries. Media players available in Debian such as VLC and Mplayer make use of these libraries in order to provide support for playback of files encoded through these many different codecs.

In summary, when you install a media player available from Debian, many different codecs the media player supports will be automatically installed. Chances are, the codecs you will ever wish to use will be the ones automatically installed with the media player. If however, you find that a codec you need isn't available from your media player, you may need to install a few extra packages. How to install these extra packages, some from Debian and some available through third parties, is explained below.

Extra codec packages from Debian

Testing/Unstable Suite

As mentioned in the previous section, the libav/ffmpeg libraries are used to provide codecs for many different media players. There are alternate versions of these library packages that provide extra codecs.

So at any one time, only one of the two packages can function/sit in a user's system.

Codec packages from third parties

Warning

Installation of third party packages is not recommended. Use at your own risk.

This section describes installation of packages from third party repositories. The packages in these repositories are not as thoroughly tested as packages in the official Debian archive. The problems with third party packages can include, but is not limited to

Package conflicts between packages in the Debian archive and packages in third party repositories.

Bad package upgrades between Debian releases.

Difficulty removing third party packages once installed.

Removal of unrelated packages to satisfy dependencies for third party packages.

Third party packages overriding/ignoring local system/user configurations.

As such, it is not recommended to install packages from third party repositories.

In any case, some codecs are only available through third party repositories. There are various reasons why they are not included within Debian. The reasons include some codecs are currently only available in the form of binary blobs and licensed under terms that prevent their redistribution.

deb-multimedia.org

There is at least one extra codec package available for amd64 and i386 machines that is not available from Debian. On amd64, the package is w64codecs, and on i386, the package is w32codecs. These extra packages provide support for a few rarely used codecs and the only software that makes use of them are xine and mplayer. If you are not using xine or mplayer or find that you don't need these codecs at all, there is no point in installing these packages.

These packages are made available from the unofficial repository deb-multimedia.org. This repository can be added to apt sources list but is known to cause problems on users' systems, including all the problems mentioned above. Because of this, and since only one package from this repository provides extra codecs, this section will only describe how to download the extra codec package and install it. Below are the two commands that will install this codec package, depending on your system (you need to be root).

Note: Installing these packages directly using dpkg saves polluting your APT sources with potentially untrustworthy third-party repositories; however, these packages won't be updated automatically if there is a new version on the repository.

DVD Playback

DVDs are usually encrypted with CSS. CSS is not a codec. In any case, here is some information on playback of encrypted DVDs. All media players use libdvdcss2 in order to playback these encrypted DVDs.

libdvdcss2 is not available in the official Debian repositories. Details on where to get libdvdcss2 from are described at CDDVD#DVD.

Legal Issues

As long time users of Debian may know, there has been a long history of legal concerns when it comes to using various multimedia related software due to software patents. Because of this, various multimedia codecs could not be made available within Debian. However, Debian's position on software patents has changed, resulting in the inclusion of these various multimedia codecs within Debian.

For information on Debian's position with regards to software patents, see the following.